Automatic drain valve



Feb. 9 9 W280 "L572J35 I C. P. Gflfiii AUTOMATIC DRAIN VALVE Filed Sept. 27, 1923 INVENTOR OHRiSTOPHER P. CASS ATTORNEY Patented Feb. 9, 1926.

PA NT CHRISTOPHER 2. CASS, or, BERKELEY, CALIFORNIA, assienoa ro T E WESTING- "Hot-Isa AIRBRAKE COMPANY, or WILMERDING', PENNSYLVANIA, A consona- TION OF PENNSYLVANIA.

AUTOMATIC DRAIN VALVE.

Application filed September 27, 1923. Serial No. 665,112.

To all whom it may concern:

Be it known that I, CHRISTOPHER P. (less, a citizen of the United States, residing at Berkeley, in the county of Alameda and State of California, have invented new and useful Improvements in Automatic Drain Valves, of which the following is a specification.

This invention relates to drain valves for automatically draining fluid pressure storage reservoirs of liquid which accumulates therein. 7

The principal object of my invention is to provide an improved automatic drain valve of the above character.

In the accompanying drawing, the single figure is a diagrammatic view, illustrating my improved drain valve applied to a storage reservoir.

Accoiiding to my invention, the drain valve is designed to be employed in connection with a fluid pressure brake system and is adapted to open when fluid is supplied to the brake cylinder to apply the brakes.

As shown in the drawing, the drain valve may comprise a casing 1 having a valve chamber 2 connected by pipe 3 with a reservoir 4 in which fluid under pressure is stored. The valve chamber 2 contains a valve 5 for controlling communication from pipe 3 to a drain outlet 6 and said valve is provided with an operating stem 7 which is mounted in a bore of the piston stem 8 of a piston 9. a

In chamber 10 at one side of piston 9 is a coil spring 11 acting on piston 9 and said chamber is connected by pipe 12 to a timing reservoir. 13.

The usual brake cylinder 14 is connected to chamber 15 at the opposite side of piston 9 and said piston is provided with an equalizing port 16.

In operation, when the brakes are not applied, the chamber 15 will be at atmos pheric pressure and spring 11 will maintain piston 9 in its outer position as shown in the drawing, permitting spring 17 to maintain the drain valve 5 seated.

IVhen the brakes are applied, fluid under pressure will also be supplied from the brake cylinder 14 to chamber 15 and piston 9 will thereupon be moved to the right, so

16, the spring 11 will be effective to shift the piston 9 to the left, permitting the drain valve 5 to close. When the brakes are re leased, fluid under pressure in chamber 15 is also released, as well as fluid in the timing reservoir 13 and chamber 10 by way of the restricted port 16. T

In order to prevent possible leakage from the brake cylinder past the stem 7 when the brakes are applied, the end of the stem 9 may be arranged to seat on a gasket 18 when the piston 9 isshifted to its right hand position.

The above described construction utilizes the fluid pressure employed to apply the brakes for opening the drain valve, but the drain valve is prevented from remaining open throughout the brake application which would tend to waste fluid under pressure in the storage reservoir by escape past the drain valve, since the operation of the timing feature causes the drain valve to be closed after a predetermined time period which can be made of short duration,

7 just suflicient to permit the desired draining of the reservoir.

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is z- 1. The combination with a reservoir, of a valve for draining said reservoir, a brake cylinder, means operated by fluid under pressure supplied to the brake cylinder for opening said valve, and a timing reservoir, an increase in pressure in which tends to operate said means to permit said valve to close.

2. The combination with a reservoir, of a valve for draining said reservoir, a brake cylinder, a piston operated by fluid supplied to the brake cylinder for opening said valve, means for equalizing the fluid pressures on opposite sides'of said piston, and a spring tending to move said piston to a position permitting the drain valve to close.

3. The combination With a reservoir, of a valve for draining said reservoir, a piston 5 for operating said valve, a brake cylinder connected to one side of said piston, and a timing reservoir connected to the opposite side of said piston, said piston having a restricted equalizing port for establishing communication from one side to the other sideof the piston.

In testimony whereof I have hereunto set my hand. a CHRISTOPHER P CASS. 

